EastEnders' Lucy Beale - played by Hetti Bywater - will be killed off this Spring in a mysterious whodunnit plot

The 20-year-old businesswoman - played by Hetti Bywater - will be killed off this Spring in the soap's biggest whodunnit plot, which will start a brand new dark chapter for the Beale family.

Lucy will be brutally slaughtered by a fellow resident, but bosses are keen for the storyline to be as big as the, 'Who Shot Phil Mitchell?' plot in 2001, so are withholding the identity of the killer until next year.

The mystery will give Adam Woodyatt - who plays Lucy's father Ian - a chance to "shine" following his alter-ego's successful breakdown storyline last year, which saw him flee Walford and return as a tramp.

An insider told The Sun newspaper: "It's been so cleverly plotted that it isn't a typical whodunnit. It's going to be raw, emotional and gritty.

"It will see her dad Ian start to question how well he really knew his daughter as secrets spill out after her death.

"But one Walford resident has a very dark secret about it -- and viewers will be left guessing for the rest of the year."

Meanwhile, Lucy - who has been played by four actresses since 1993 - will be murdered a month before rival soap 'Coronation Street' feature Tina McIntyre - played by Michelle Keegan - being killed off.